optimize directory structure

lib/middleware/cache-common.js

@@ -0,0 +1,65 @@
+const pathToRegExp = require('path-to-regexp');
+const readall = require('readall');
+const crypto = require('crypto');
+
+const paired = (route, path) => {
+    const options = {
+        sensitive: true,
+        strict: true,
+    };
+
+    return pathToRegExp(route, [], options).exec(path);
+};
+
+// eslint-disable-next-line no-unused-vars
+const read = (stream) =>
+    new Promise((resolve, reject) => {
+        readall(stream, (err, data) => {
+            if (err) {
+                reject(err);
+            } else {
+                resolve(data);
+            }
+        });
+    });
+
+const md5 = (str) =>
+    crypto
+        .createHash('md5')
+        .update(str)
+        .digest('hex');
+
+const validityCheck = (routes, exclude, path) => {
+    let match = false;
+    let routeExpire = false;
+
+    for (let i = 0; i < routes.length; i++) {
+        let route = routes[i];
+
+        if (typeof routes[i] === 'object') {
+            route = routes[i].path;
+            routeExpire = routes[i].expire;
+        }
+
+        if (paired(route, path)) {
+            match = true;
+            break;
+        }
+    }
+
+    for (let j = 0; j < exclude.length; j++) {
+        if (paired(exclude[j], path)) {
+            match = false;
+            break;
+        }
+    }
+
+    return { match, routeExpire };
+};
+
+module.exports = {
+    paired,
+    read,
+    md5,
+    validityCheck,
+};